Question

Calculate the Total Hardness (TH), Carbonate Hardness (CH), Non-Carbonate Hardness (NCH), and Total Dissolved Solids (TDS) for each source? Place your answer in the table provided below indication appropriate units Water SourceTH CH NCH TDS McDonald's Well Dontgointhere Lake

Answer 1

MCDONALD'S WELL STEP I: TOTAL HARDNESS (TH) TH = [Ca^2 +]/EQUIVALENT WEIGHT OF Ca^2 + times EQ.WT.OF CaCo_3 + [Mg^2 +]/EQ.WT.OF Mg^2 + times EQ.WT.OF CaCo_3 = 255/20 times 50 + 125/12.2 times 50 = 1150 mg/L as CaCo_3 [OR] 23 mg/L. STEP II: CARBONATE HARDNESS (CH) CH IS EQUAL TO TH OR ALKALINITY, WHICHEVER IS LESS. ALKALINITY = [H Co^-_3]/EQ.WT.OF HCo^-_3 times EQ. WT. OF CaCo_3. = 775/61 times 50 = 635.25 mg/L as CaCo_3 [OR] 12.7 mg/L. So, CH = 635.25 mg/L as CaCo_3 [OR] 12.7 mg/L. STEP III: NON - CARBONATE HARDNESS (NCH) TH = CH + NCH So, NCH = TH - CH = 1150 - 635.25 = 514.75 mg/L as CaCo_3 [OR] 10.30 mg/L. STEP IV: TOTAL DISSOLVED SOLIDS (TDs) TDs = summation CATIONS + summation ANIONS = 255 + 125 + 80 + 775 + 320 + 200 = 1755 mg/L.